Process for producing solutions of insoluble gums.



III SATES PATENT BEIGE.

EDUARD SIEFERT-SCHWAB, OF NEUNKIRCHEN, AUSTRIA-HUNGARY.

PROCESS FOR PRODUCING SOLUTIONS OF INSOLUBIiE GUMS.

No Drawing.

T 0 all whom it may concern Be it known that I, Eounno SIEI:I IRT- Sonwan, subject of the King of Spain, rcsiding at Neunkirchen, Lower Austria, Austria-Hungary, have invented certain new and useful Improvements in the Process for Producing Solutions of Insoluble Gums, of which. the following is a specification.

The so-called insoluble gums, which in contra-distinction to the soluble gums, such as gum Senegal cordofan gum, Ghatti gum and the like only swell in cold water without ever dissolving in the same, may be divided into two groups, one group comprising those gums which possess neutral or practically neutral reaction, such as Bassora gum, and the other those of a pronounced acid character, such as Indian tragacantn. Those gums which reveal a neutral or practically neutral reaction, remain perfectly insoluble even when boiled for some considerable time in pure water, but can be dissolved by prolonged boiling when mineral acid is added. Those insoluble gums which are of a pronounced acid character (particularly Indian tragacanth) are gradually dissolved when boiled for some considerable time in pure water in an open boiler or for a shorter time in an autoclave, which however, has the disadvantage that they become more and more diluted by continued boiling. This dilution of the already dissolved gum particles renders it impossible to obtain a thick solution suitable for dressing purposes, as the solution of the gum particles progrosses from the outside inwardly, and the gum particles which were first dissolved have already entered the stage of liquefaction when the inner gum particles have just begun to be dissolved. This drawback is not remedied by an extensive comminution of the gum mass, because the pulverulent particles adhere together in the boiler and form a compact mass. Similarly ineffective is the already attempted addition of peroxid of hydrogen, as the presence of the latter not only accelerates the dissolving but also practically to the same extent hastens the liquefaction or dilution of the dissolved particles. The addition of mineral acids, however, has no influence whatever on the dissolution conditions of the acid reacting gums. It has been found that this dilution of the already dissolved gum is prevented wholly or for the greater part if hydroxids Specification of Letters Patent.

Application filed October 29, 1912.

Patented July 8, 1913.

Serial No. 728,459.

of alkali and alkaline earth metals, or substances acting similar to these, such as carbonates, are added to the water used for the dissolving of the gum. The maximum ell'ect is obtained if these substances are added in such quantities that the end product is just neutral. It is, however, sullicient to employ also smaller quantities in order to considerably retard further dilution. This thickening effect of the alkalis on Indian tragacanth, on which effect this invention is based, has nothing to do with the well known dissolving action of the alkalis on the insoluble parts of genuine tragacanth, which in every respect differs from Indian tragacanth) and of the gums possessing only a w ark acid reaction.

Indian tragacanth to which the new process is chiefly to be applied distinctly differs from genuine tragacanth and the other kinds of gums. All the latter possess the well known phl0ro-glucinol react-ion (consisting in the red coloring on boiling with hydrochloric acid and phloro-glucinol) which reaction is only about in the Indian tragacanth. This fact clearly points to a substantially different chemical constitution. IVhereas further the genuine tragacanth contains starchy substances or particles, the same are entirely absent in Indian tragacanth. The latter is further characterized by its great acidity when compared with all other kinds of gums and tragacanth. Finally also the dissolving capacities of these substances are absolutely different. A characteristic feature of Indian tragacanth is that it is insoluble in cold water, whereas it easily dissolves when boiled without it being necessary to make any additions of the substances. The other kinds of gums and tragacanth behave quite differently in this respect. This solution of Indian tragacanth obtained by boiling is as already hereinbefore mentioned too thin particularly for textile purposes, and the invention consists in the addition of substances with an alkaallowed to swell, whereupon the same is boiled in an open boiler or an autoclave until it forms a solution.

Example 11: The caustic soda is replaced by 1 kg. of calcium hydroxid, the remainder of the procedure being the same as described in connection with Example 1.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is:

A process for producing solutions of insoluble gums possessing an acid reaction by boiling in water, which consist in adding non-oxidizing substances having an alkaline reaction to the water. 7

In testimony whereof I afiix my signature in the presence of two Witnesses.

EDUARD SIEFERT-SCH /VAB.

Vitnesses FRIEDRICH BINDER, AUGUsT FUGGER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

